riginally developed by the Ismagilov lab at the University of Chicago, nanovolume plug-based microfluidic protein crystallization is an emerging technology for efficient protein use for crystallization trials in conjunction with in situ X-ray imaging. deCODE and its microfulidic device collaborators have produced several different plastic labcards that contain of the required microfluidic circuitry to prepare several hundred nanovolume (~20 nl) protein crystallization experiments as aqueous plugs that are carried in a microfluidic channel by an inert fluoropolymeric oil (fluorinert). Three aqueous microfluidic channels for protein, buffer and precipitant converge in a mixer circuit together with the fluorinert carrier fluid (a “3+1 Mixer”). Microsyringe pumps controlled by Microplugger™ software drive the formation of nanovolume aqueous plugs into the fluorinert carrier fluid which enters a long microfluidic holding circuit where final nanovolume crystallization experiments are stored.

Functional 3+1 Mixer + channel holder labcards made out of cyclic olefin copolymer (COC) and polycarbonate (PC) material have been produced with chemical treatments that lower the surface energy of the microfluidic circuitry, making it functional for nanovolume aqueous plug formation. The labcards have proved to be of reasonable reliability in running gradient method nanovolume plug-based protein crystallizations using test proteins (lysozyme and thaumatin) as well as other experimental proteins. In situ X-ray diffraction on in-house sources have been demonstrated for both COC and PC types of labcards with reasonable success. deCODE recently presented the technology together with the Ismagilov lab at the Brookhaven Crystallization Course. More details can be found here: http://technology.lbl.gov/portal/?pag…